Trichothyas (Neothyas) zhangae Li, Jin & Guo, 2024

LiK, Hai-Tao, SmitK, Harry, K, Xin-Yao Gu, JinK, Dao-Chao & GuoK, Jian-Jun, 2024, The first records of the subfamily Euthyadinae K. Viets, 1931 (Acari, Hydrachnidia, Hydryphantidae) from China with description of one new species, Acarologia 1931 (1), pp. 105-122 : 114-120

Trichothyas (Neothyas) zhangae Li, Jin & Guo sp. nov. ( Figures 9–15 )

Zoobank: A118D8F4-34DA-4D5E-8B6B-DEF1E6BA0D02

Habitat — Turbulent current with organic detritus, gravels and cobblestones in the mountain.

Material examined — Holotype: adult male, Mount Huangshan World Geopark , Anhui Province, P. R. China (30°04′41″N, 118°09′01″E, 530 m a.s.l.), collected by Xu Zhang, 20-V-2010. Slides No. AH-HY-2010052006 . Allotype: adult female, same data as holotype, slides No. AH-HY-2010052007. Paratype: four adult males and two adult females, same data as holotype, Slides No. AH-HY-2010052008–2010052013.

Etymology — This new species is named after Dr Xu Zhang (P. R. China) in appreciation

of providing the specimens and her brilliant contribution on water mites taxonomy.

Diagnosis — All dorsal plates separated; D 2 slightly behind posterior edge of FS; middle margin of ACG with two rows of feathered setae; C 2 rounded under SEM, but with sclerotization beneath integument under optical microscope; PCG widely separated; genital field with three pairs of acetabula, GF extended from the middle of Ac-1 to Ac-3, Gp relatively long, extending to frontal margin of third acetabula; a round CP bigger than V 3 ; EP with sclerotized extension; a pair of V 1 separated; P-4 terminal with a seta-liked protrusion; I-L-3 without two strong dorsal peg setae. Male. PS trapezoidal. Female. PS triangular.

of chelicera.

Description — Male (n=5). Integument papillae bluntly pointed, interspaces with fine lineation ( Figure 9A ). In dorsal view: apical angles of Cx-I and Cx-II visible in dorsal view; all dorsal plates separated; FS inverse isosceles trapezoid, with median eye, O 2 and five muscle attachments; D 2 slightly behind posterior edge of FS; ACP with a muscle attachment in the middle; PCP with a pair of muscle attachment; all LP with a muscle attachment, LP 1 and 4 triangle, LP 2 and 3 trapezoidal ( Figure 10A ). In ventral view: middle margin of ACG with two rows of feathered setae most dense near the base of ACG ( Figure 11A–B ); C 2 rounded under SEM, but with sclerotization beneath integument under optical microscope ( Figures 9B , 10B ); PCG widely separated ( Figure 10B ); genital field with three pairs of acetabula, PS trapezoidal, GF extended from the middle of Ac-1 to Ac-3, Gp relatively long, extending to frontal margin of third acetabula ( Figure 10B ); a round CP bigger than V 3 ; EP with sclerotized extension; a

pair of V 1 separated ( Figure 10B ). In lateral view: except L 1 and L 4, four sclerotized plates with varying shapes near the body axis close to each other ( Figure 10C ). In frontal view: A 1 fused with a triangular plate, lateral eyes attached to O 1 platelets ( Figure 10D ). In rear view: V 4 close

to LP 4 but not fused ( Figure 10E ).

Gnathosomal base long and slender ( Figure 9C ). Chelicera base relatively long; chela with teeth on one side ( Figure 9D ). Palp five-segmented ( Figure 12A, C ); P-1 short, with two feathered setae; P-2 with three dorsal and two lateral feathered setae; P-3 with two dorsal feathered setae; P-4 terminal with three setae and a seta-liked protrusion ( Figure 12B, D ); venter of P-5 with a mini seta on one side ( Figure 12B, D ).

Legs robust: I-L-3 without two strong dorsal peg setae.

Female (n=3). Similar to the male except larger idiosoma and PS wider ( Figures 11C–D , 13–15 ).

Measurements — Male (n=5). I L/W 964 (874–964)/714 (670–714); FS L/W 300 (251–

300)/378 (363–378); ACP L/W 160 (144–164)/186 (165–186); PCP L/W 196 (178–198)/283

(241–283); LP 1–4 L/W 246 (232–246)/132 (129–138), 229 (179–229)/213 (190–213), 198 (198–215)/180 (145–180), 210 (202–210)/258 (221–258). ACG L/W 272 (247–272)/205 (182–205); PCG L/W 273 (239–273)/221 (211–221); PS L/W 60 (53–62)/62 (47–62); Gp L 201 (193–210); GF L 209 (183–209); Ac-1–3 L/W 76 (63–76)/30 (24–30), 74 (71–74)/24 (24–30), 63 (57–66)/53 (43–53); EP L 15 (15–16); CP L/W 79 (57–79)/70 (48–70). G L 265 (246–265); CB L 185 (170–185), CC L 73 (68–73); Palp segments L: P-1–5 32 (27–32), 89 (83–89), 48 (41–48), 106 (106–111), 38 (38–39). Leg segments L: Ⅰ-L-1 68 (67–71), Ⅰ-L-2

144 (136–144), Ⅰ-L-3 68 (68–70), Ⅰ-L-4 90 (90–92), Ⅰ-L-5 105 (102–105), Ⅰ-L-6 103 (99–103);

II-L-1 76 (76–80), II-L-2 159 (146–159), II-L-3 74 (69–74), II-L-4 106 (106–111), II-L-5

122 (117–122), II-L-6 137 (137–148); III-L-1 80 (80–95), III-L-2 146 (138–146), III-L-3

68 (64–68), III-L-4 92 (92–102), III-L-5 107 (107–112), III-L-6 127 (127–131); IV-L-1 150 (142–150), IV-L-2 181 (172–181), IV-L-3 112 (109–112), IV-L-4 184 (184–188), IV-L-5 140 (140–143), IV-L-6 134 (132–139).

Female (n=3). I L/W 1018 (1018–1082)/771 (771–885); FS L/W 302 (302–360)/377 (377–409); ACP L/W 170 (170–183)/192 (192–209); PCP L/W 202 (202–230)/301 (301–318);

LP 1–4 L/W 239 (239–259)/172 (172–187), 230 (230–238)/236 (236–264), 216 (216–237)/204 (204–207), 216 (198–216)/275 (275–285). ACG L/W 271 (271–287)/201 (201–206); PCG L/W 271 (271–282)/235 (235–258); PS L/W 44 (42–44)/89 (89–97); Gp L 224 (224–236); GF

L 218 (218–232); Ac-1–3 L/W 71 (71–79)/36 (30–36), 83 (79–83)/29 (29–32), 76 (75–76)/48

(48–49); EP L 19 (18–19); CP L/W 49 (49–52)/48 (44–48). G L 260 (260–284); CB L 197

(192–197), CC L 75 (75–88); Palp segments L: P-1–5 33 (33–40), 91 (91–97), 47 (47–58),

114 (114–120), 38 (38–39). Leg segments L: Ⅰ-L-1 73 (73–88), Ⅰ-L-2 134 (134–144), Ⅰ-L-3

66 (66–72), Ⅰ-L-4 90 (90–106), Ⅰ-L-5 104 (102–104), Ⅰ-L-6 102 (102–107); II-L-1 73 (73–89), II-L-2 155 (155–178), II-L-3 67 (67–77), II-L-4 110 (110–129), II-L-5 120 (120–140), II-L-6 143 (143–154); III-L-1 78 (78–82), III-L-2 142 (142–155), III-L-3 69 (69–71), III-L-4 104 (104–114), III-L-5 114 (114–126), III-L-6 134 (134–149); IV-L-1 146 (146–169), IV-L-2 184

(184–195), IV-L-3 107 (107–132), IV-L-4 193 (193–224), IV-L-5 142 (142–161), IV-L-6 140

(140–155).

Remarks — Previously, only one species of the subgenus Neothyas was known, i.e. Trichothyas (Neothyas) hygropetrica Lundblad, 1941 from Indonesia (Table 1). Unfortunately,

the female T. (N.) hygropetrica was not described by Lundblad (1941). Therefore, only males

of the two species are compared here. Trichothyas zhangae sp. nov. from Anhui differs from T. hygropetrica in the following characters: (1) PS of T. (N.) zhangae Li, Jin & Guo sp. nov.

is bigger than T. (N.) hygropetrica ; (2) GF extends from the middle of Ac-1 to Ac- 3 in T. (N.) zhangae Li, Jin & Guo sp. nov., while the anterior margin of GF is behind Ac- 1 in T. (N.) hygropetrica ; (3) Round CP of T. (N.) zhangae Li, Jin & Guo sp. nov. is relatively bigger than irregularly shaped CP of T. (N.) hygropetrica ; (4) EP is with sclerotized extension in T. (N.) zhangae Li, Jin & Guo sp. nov., but not existed in T. (N.) hygropetrica ( Lundblad 1941 ; Cook

1974; Smit 2020).

Distribution — China ; only known from the locus typicus.

Figures

Figure 9 Trichothyas (Neothyas) zhangaeLi, Jin & Guo sp. nov., ♂ (AH-TR-2010052008), SEM photographs: A – Papillary integument; B – CoxoglandulariaC 22(); C – Gnathosoma; D – One side

Figure 10 Trichothyas (Neothyas) zhangaeLi, Jin & Guo sp. nov., ♂, holotype (AH-TR-2010052006), optical microscope photographs: A – Dorsal view; B – Ventral view; C – Lateral view; D – Frontal view; E – Rear view. Scale bars = 200 μm.

Figure 11 Trichothyas (Neothyas) zhangaeLi, Jin & Guo sp. nov., SEM photographs: A – ♂ (AH- TR-2010052008), anterior coxal group (ACG); B – ♂ (AH-TR-2010052008), feathered setae on the middle margin of ACG; C – ♀ (AH-TR-2010052012), anterior coxal group (ACG); D – ♀ (AH-TR- 2010052012), genital field.

Figure 12 Trichothyas (Neothyas) zhangaeLi, Jin & Guo sp. nov., ♂ (AH-TR-2010052008), SEM photographs: A – One side of palp; B – One side of P-5; C – Another side of palp; D – Another side of P-5.

Figure 13 Trichothyas (Neothyas) zhangaeLi, Jin & Guo sp. nov., ♀, allotype (AH-TR-2010052007): A – Dorsal view; B – Ventral view; C – Lateral view; D – Frontal view; E – Rear view. Scale bars = 200 μm.

Figure 14 Trichothyas (Neothyas) zhangaeLi, Jin & Guo sp. nov., ♀ (AH-TR-2010052012), SEM photographs: A – Outer side of I-Leg-1–6; B – Inner side of I-Leg-1–6; C – Outer side of II-Leg-1–6; D – Inner side of II-Leg-1–6.

Figure 15 Trichothyas (Neothyas) zhangaeLi, Jin & Guo sp. nov., ♀ (AH-TR-2010052012), SEM photographs: A – Outer side of III-Leg-1–6; B – Inner side of III-Leg-1–6; C – Outer side of IV-Leg- 1–6; D – Inner side of IV-Leg-1–6.